1. Field of the Invention
The present invention relates to a plasma display panel (PDP) and a driving method thereof.
2. Discussion of the Background
Generally, a PDP displays images by exciting a phosphor with ultraviolet rays from gas discharge occurring in a discharge cell. The PDP may be classified as an AC type and a DC type according to driving voltage waveforms and discharge cell structure, and may be classified as a facing or surface discharge type according to electrode construction. Three electrode surface discharge type PDPs are commonly used.
A conventional three electrode, surface discharge PDP includes a plurality of address electrodes arranged in a column direction on a rear substrate and covered with a dielectric layer. Barrier ribs may be arranged in the column direction on the dielectric layer between, and in parallel with, adjacent address electrodes. A phosphor layer is typically formed on the surface of the dielectric layer and the sides of the barrier ribs. Further, a scan electrode and sustain electrode pair are arranged in parallel in a row direction on the front substrate and sequentially covered with an upper dielectric layer and a protective layer. The front and rear substrates are arranged facing each other with a discharge space formed therebetween, so that the scan electrodes and the sustain electrodes are perpendicular to the address electrodes. Discharge spaces at intersections of the address electrodes and the scan and sustain electrode pairs form discharge cells. Additionally, a PDP having a closed type of barrier rib construction has recently been applied to improve discharge properties. Such PDPs may have row barrier ribs arranged on the dielectric layer of the rear substrate such that they pass between closed discharge cells in a column direction.
Generally, in a PDP driving method, one frame may be divided into a plurality of subfields, and each subfield may comprise a reset period, an address period, and a sustain period.
The reset period is a period for erasing wall charges formed by a previous sustain discharge and for setting up the wall charge in order to stably perform a subsequent address discharge. The address period is a period for selecting cells to be turned on and turned off and for accumulating a wall charge on the turned on cell (addressed cell). The sustain period is a period for performing a sustain discharge to display an image on the addressed cell.
More specifically, in the address period, turn-on/turn-off pattern signals are applied to the address electrodes while applying a scan voltage to corresponding scan electrodes and non-scan voltages to the remaining scan electrodes. An address discharge occurs between a scan electrode and a corresponding address electrode to which the turn-on pattern signal has been applied to form a wall charge. In the sustain period, a sustain discharge waveform may be alternately applied to the sustain electrode and the scan electrode of all discharge cells, and sustain discharges occur at the discharge cells in which the wall charge is formed in the address period.
FIG. 1 shows a a conventional PDP with a closed type barrier rib construction.
As shown in FIG. 1, an address electrode 2 and a barrier rib (not shown) are arranged in a column direction, and barrier ribs 3 are arranged in a row direction, on a rear substrate 1. Further, a scan electrode 6 and a sustain electrode 7 pair are arranged on a front substrate 5 between the barrier ribs 3.
Generally, the address discharge, which is one of the most important aspects regarding PDP driving, is affected by structures (especially, the barrier rib) in the discharge space. In particular, in a PDP having the closed barrier rib structure, the address discharge may be relatively weak, thereby requiring a high address voltage.
Further, with a PDP using high pressure gas, including high partial pressure of Xe, has been developed. However, in a highly efficient PDP, the level of brightness occurring by a one time sustain discharge may be very high, which may make for poor low gray scale expression.